Pool and spa water quality control system and method

ABSTRACT

A water quality management system for a water installation containing water. In some embodiments, the system includes a water quality measurement module adapted to monitor the water quality of the water in the water installation and to send water quality information to a controller; a chemical dispensing module adapted to dispense chemicals directly into the water installation in response to signals from the controller; and a communication mechanism configured to provide communication among the controller, the water quality measurement module, the chemical dispensing module and a user.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/569,852, filed Oct. 27, 2017, which is the national phase ofInternational Application No. PCT/US2016/029293, filed Apr. 26, 2016,which application claims the benefit of U.S. Provisional Application No.62/153,373, filed Apr. 27, 2015, and U.S. Provisional Application No.62/293,167, filed Feb. 9, 2016, all of which are herein incorporated byreference in their entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare incorporated herein by reference in their entirety to the sameextent as if each individual publication or patent application wasspecifically and individually indicated to be incorporated by reference.

FIELD

The present invention relates to an affordable, modular, and convenientsystem for homeowners to deploy in their pools or spas in order tooptimally maintain the water quality in a safe and responsible way whileminimizing use of chemicals and energy.

BACKGROUND

Nearly 15 million US homeowners struggle to optimally control thequality of the water in their pools. (As used herein, “pools” includesspas.) The water is affected by environmental factors such as sunlight,wind, pollen, debris, rain and human factors such as skin bacteria,sweat and urine. Most homeowners or their hired pool service makeadjustments on a weekly basis at best. In order to deal with changingconditions, most users overdose their pools with circulatingdisinfectants, resulting in harsh water that attacks skin, hair andbathing suits, and often requiring additional chemicals to maintain pH.Water chemistry parameters are mutually dependent where free chlorine(“FC”) requires a narrow pH range in order to effectively oxidizeorganic matter and purify the water. If not enough effectivedisinfectant is present, nutrients in the pool can cause an algae bloomrequiring further expensive chemicals and environmentally damaging waterchange often in excess of 15,000 gallons. This results in over $2.6billion spent each year in the US by consumers on pool chemicals such asdisinfectants, water balance adjusters (for pH, total alkalinity,calcium hardness, and cyanuric acid), algaecides, clarifiers,flocculants, and enzymes which need to be manually administered topools. Since the popularization of back yard pools in over 15% of allhouseholds, no automatic, easy to deploy, cost effective systems havebeen commercially available to address these needs.

According to the US Department of Energy, the average pool requires1,500 kWh per year in order to operate its filtration and circulationpumps. Many pool pumps run on a timer that is not responsive to actualfiltration need. Saltwater chlorine generators also require significantpower and maintenance and are also run on a timer that is not responsiveto the actual need of disinfectant in the pools.

Nearly 90% of pool owners in the US maintain their own pools and spasand are not able or willing to make significant investment in installingnew equipment requiring plumbing or electrical connections.

Several partial solutions have been offered to the consumer. Manualcolorimetric test strips exist that indicate the state of chemicals inthe pool water, but those must be applied manually, read onmulti-colored comparison charts, and translated to the correct balancingmixture of chemicals needed. It is difficult for the user to connectthese weekly measurements and compute the dynamic trajectory of poolwater and the required corrective action. This results in over or undercorrection both of which can be very expensive.

There exist some automation systems for the residential pool market(e.g., the Hayward Sense and Dispense® system). These systems are costlyto install and costly to maintain. In addition, they require adisruption of existing plumbing. These systems control only for chlorineand pH and have oxidation-reduction potential (ORP) sensors with asensitive platinum electrode and pH sensors with a sensitive glass bulb,both of which need regular maintenance for calibration and cleaning.

Dosing disinfectant using tricholoroisocyanuric acid (“trichlor”) puckseluting chlorine from a floating dispenser are the most common. Mostusers do not bother to manually adjust the dispensing rate in responseto pool chlorine demand, however. An inline chlorinator/feeder also usestrichlor pucks, but its dispensing rate is also rarely manuallyadjusted. Both trichlor dispensing systems require users to handle ahazardous chemical oxidizing puck when these dispensers have to bereplenished. Saltwater chlorine generators work on timers that also arerarely manually adjusted based on chlorine demand.

Balancing the pH, alkalinity, and calcium levels of the pool waterrequires additional measurements, calculations and manual administrationof chemicals.

It should be further appreciated that all the processes affecting poolwater chemistry mentioned above are not linear, yet users routinelyattempt to control them with step adjustments such as adding a fixedamount of chemicals, or changing the setting on a chlorine dispenser,pump timer, etc. subject to infrequent measurement, typically once perweek at best. This approach inevitably results in suboptimaladjustments. The present invention describes a modular battery operatedsystem that may be easily deployed one module at a time to deal with thetedious aspects of pool maintenance and relieves the user from thesemanual tasks and makes repeated measurements and optimized dynamicdosing to keep pool water in ideal condition.

It should be further appreciated that pool service personnel currentlyuse fixed schedules and routes resulting in either visiting pools ontheir route too frequently or too infrequently often involvingconsiderable driving time and expense. The present inventionautomatically takes care of most maintenance issues, advises the servicecenter of pool conditions and often proactively reports service issuesbefore they become problems, thereby allowing pool service personnel toperform their work more efficiently by minimizing truck rolls andoptimizing routing based on actual service need.

It should be further appreciated that any man-made body of water mayrequire chemical monitoring and adjustment. Cooling towers have to beroutinely maintained with sanitizer to avoid bacteria growth that canlead to Legionnaires' disease. In addition to cooling towers, hot tubs,fountains, koi ponds, containment ponds and other open or closed watersystems could benefit from one or more of the modules described hereineach of which is of low cost, requiring no complex calibration orcleaning, and all but one (the pump control module) are easily added tothe pool by the pool owner without need for professional installation.

Colorimetric strips (e.g., Hach Aquachek®, ITS Sensafe®, LaMotteInsta-TEST®) have been available for decades and are the most popularmeans for analyzing the key analytes in pool water such as FC, pH,alkalinity, and hardness. These pad strips must be manually dipped inthe water and the color of the pads compared to a standard chart to readthe analyte level. The pad strips must be kept in a sealed container sothey do not degrade due to exposure to moisture in the form of liquidwater or water vapor present in humid air.

Electronic probes for measuring pH and ORP (which is related to, but nota direct measurement of FC) have been available in commercial systems,but these probes are prone to degradation and calibration drift. Whilesome of these systems simply provide open loop monitoring, otherscontrol the dispensing of chemicals based on monitored parameters, suchas in U.S. Pat. No. 8,797,523.

Automated pool chemical sensing technology suffers from certaindrawbacks. For example, systems have been proposed to sequentiallyexpose pads to pool water as described in U.S. Pat. No. 6,113,858 andU.S. Pat. No. 8,197,755 or as demonstrated by the Blue I WaterTechnologies PRIZMA® system(http://www.blueitechnologies.com/products/prizma/), but they do notprovide for a way to prevent moisture degradation to the analyte pads orthe ability to keep them in the pool water prior to use.

In addition to water chemical monitoring, turbidity monitors have beenused to control water circulation pumps in pools, such as described inUS Publ. No. 2011/0253638. Circulating water pumps have also beencontrolled based on pool usage, as described in U.S. Pat. No. 5,804,080.

SUMMARY OF THE DISCLOSURE

One aspect of the invention provides a water quality management systemfor a water installation containing water. In some embodiments, thesystem includes a water quality measurement module adapted to monitorthe water quality of the water in the water installation and to sendwater quality information to a controller; a chemical dispensing moduleadapted to dispense chemicals directly into the water installation inresponse to signals from the controller; and a communication mechanismconfigured to provide communication among the controller, the waterquality measurement module, the chemical dispensing module and a user.

In some embodiments, the water quality measurement module may be adaptedto float in the water. Alternatively or additionally, the water qualitymeasurement module may have a plurality of colorimetric test pads, eachtest pad enclosed in a water and vapor-proof barrier, a sensor adaptedto sense a color change in a test pad and a motor adapted to advance atest pad into the water and to breach the barrier to permit water toreach the test pad.

In any of the preceding embodiments, the water quality measurementmodule may include a water temperature sensor, the controller beingconfigured to adjust chemical dispensing based on a water temperaturesignal from the water temperature sensor.

In any of the preceding embodiments, the water quality measurementmodule may include an air temperature sensor, the controller beingconfigured to adjust chemical dispensing based on an air temperaturesignal from the air temperature sensor.

In any of the preceding embodiments, the water quality measurementmodule may include a hydrophone, the controller being configured toadjust chemical dispensing based on a sound signal from the hydrophone.

In any of the preceding embodiments, the water quality measurementmodule may include a water turbidity sensor, the controller beingconfigured to adjust operation of a water pump based on a turbiditysignal from the water turbidity sensor.

In any of the preceding embodiments, the water quality measurementmodule may include an air humidity sensor, the controller beingconfigured to adjust chemical dispensing based on a humidity signal fromthe humidity sensor.

In any of the preceding embodiments, the water quality measurementmodule may include an accelerometer.

In any of the preceding embodiments, the chemical dispensing module maybe adapted to float in the water.

In any of the preceding embodiments, the chemical dispensing module maybe adapted to maintain orientation and buoyancy as chemicals aredispensed.

In any of the preceding embodiments, the chemical dispensing module mayinclude a collapsible bladder containing a chemical to be dispensed intothe water. In such embodiments, the system may also have a chemical portcommunicating with the bladder and adapted to be underwater.

In any of the preceding embodiments, the system may include a ventadapted to vent gas generated by the chemicals.

In any of the preceding embodiments, the chemical dispensing module mayinclude a quantity of the chemicals enclosed in a water-dissolvablepackage and disposed in a chemical chamber.

In any of the preceding embodiments, the chemical dispensing module mayinclude a compartment arranged and configured to trap gases released bythe chemicals. In some such embodiments, the controller may beconfigured to activate an opening in the compartment to release thegases.

In any of the preceding embodiments, the chemical dispensing module mayinclude a sensor adapted to sense depletion of the chemical in thechemical dispensing module.

In any of the preceding embodiments, the chemicals may be disposed indoses sealed in waterproof packets, the chemical dispensing moduleincluding a motor configured to release a dose of chemicals from apacket.

In any of the preceding embodiments, the system may also include a pumpmodule adapted to control pumping of the water in response to signalsfrom the controller.

Another aspect of the invention provides a water quality measurementapparatus adapted to monitor water quality of a water installation. Insome embodiments, the water quality measurement apparatus including aplurality of colorimetric test pads, each test pad enclosed in a waterand vapor-proof barrier film; a sensor adapted to sense a color changein a test pad; and a motor adapted to advance a test pad and to breachthe barrier to permit water to reach the test pad.

In some embodiments, the water quality measurement apparatus is adaptedto float in the water.

In any of the preceding embodiments, the water quality measurementapparatus may include a battery adapted to provide power to the motor.

In any of the preceding embodiments, the water quality measurementapparatus may include a communication mechanism configured to providecommunication with other water installation components and/or theInternet.

In any of the preceding embodiments, the water quality measurementapparatus may include a sensor adapted to sense a water parameter, theapparatus being adapted to determine water installation chemical dosingbased on information from the sensor and/or from the Internet.

Yet another aspect of the invention provides a chemical sanitizerdispensing apparatus adapted to dispense chemical sanitizer into a waterinstallation. In some embodiments, the apparatus has a housing adaptedto extend into water in the water installation; a chemical compartmentin the housing and containing sanitizer chemicals; a port extendingbetween the compartment and an exterior portion of the housing; ashutter movable between a first position blocking the port and a secondposition exposing the port; and a motor adapted to move the shutterbetween the first and second positions.

In some embodiments, the housing may be adapted to float in the water.

In any of the preceding embodiments, the chemical sanitizer dispensingapparatus may include a battery adapted to provide power to the motor tomove the shutter.

In any of the preceding embodiments, the chemical sanitizer dispensingapparatus may include a communication mechanism configured to providecommunication with other water installation components and/or theInternet.

In any of the preceding embodiments, the chemical sanitizer dispensingapparatus may include a controller adapted receive informationpertaining to water installation pump operation and/or temperatureinformation to determine port exposure times for exposing sanitizerchemical to the water.

In any of the preceding embodiments, the chemical sanitizer dispensingapparatus may include a water dissolving film surrounding the sanitizerchemicals.

In any of the preceding embodiments, the chemical sanitizer dispensingapparatus may include a controller adapted to receive information aboutwater installation use and a vent mechanism adapted to vent gasgenerated by the sanitizer chemicals when the water installation is notin use.

Still another aspect of the invention provides a chemical dispensingapparatus adapted to dispense a chemical into a water installation. Insome embodiments, the chemical dispensing apparatus includes a pluralityof chemical packets each arranged in a strip and packaged in a barrierfilm, each packet containing a dose of chemical; and a packet openingmechanism adapted to dispense a dose of chemical within a packet intothe water.

In some embodiments, the chemical dispensing apparatus includes ahousing adapted to float in the water installation, the housingsupporting the strip and the packet opening mechanism.

In any of the preceding embodiments, the packet opening mechanism mayinclude a battery and a battery-operated motor.

In any of the preceding embodiments, the chemical dispensing apparatusmay include a communication mechanism configured to providecommunication with other water installation components and/or theInternet.

Yet another aspect of the invention provides a chemical dispensingapparatus adapted to dispense a chemical into a water installation. Insome embodiment, the chemical dispensing apparatus includes a movableplatform adapted to support a dissolvable chemical beneath the surfaceof water in the water installation; a reservoir sealable from the waterin the water installation; and a motor adapted to move the platform to aposition in which the dissolvable chemical is inside the reservoir.

In some embodiments, the chemical dispensing apparatus also includes ahousing extending below the reservoir, the housing containing at leastone opening, the platform being movable between a position in which thedissolvable chemical communicates with the opening and the position inwhich the dissolvable chemical is inside the reservoir.

Still another aspect of the invention provides a chemical dispensingapparatus adapted to dispense a chemical into a water installation. Insome embodiments, the chemical dispensing apparatus includes a housingadapted to float in the water installation; a collapsible bladderadapted to contain the chemical; and a discharge port adapted todischarge the chemical from the bladder.

Yet another aspect of the invention provides a pump control apparatusadapted to control a water circulation pump in a water installation. Insome embodiments, the pump control apparatus includes an electricalcurrent and/or sensor adapted to generate sensor signal; and acontroller adapted to determine at least one of pump load and filtrationsystem service condition from the sensor signal.

In some embodiments, the pump control apparatus also includes acommunication mechanism configured to provide communication with otherwater installation components and the Internet to optimize pumpoperation. The pump control apparatus may be further adapted to operatethe pump in response to a water turbidity measurement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C show three views of a strip of test pads for use ina water quality measurement apparatus according to an aspect of theinvention. FIG. 1A is a side view. FIG. 1B is a top view. FIG. 1C is aperspective view.

FIG. 2 shows a water quality measurement apparatus according to anaspect of the invention employing the strip of test pads shown in FIG.1.

FIG. 3 is a schematic rendering of the sensing and control elements ofthe water quality measurement apparatus of FIG. 2.

FIG. 4 is a detailed partial view of the water quality measurementapparatus of FIG. 2.

FIG. 5 shows a chemical dispensing apparatus according to an aspect ofthe invention.

FIG. 6 shows a water pump control apparatus according to an aspect ofthe invention.

FIGS. 7A, 7B and 7C show aspects of a chemical sanitizer dispensingapparatus according to an aspect of the invention.

FIG. 8 shows components of a modular pool water maintenance systemaccording to an embodiment of the invention.

FIG. 9 shows a water turbidity monitoring apparatus according to anaspect of the invention.

FIG. 10 shows a spa water maintenance apparatus according to an aspectof the invention.

FIG. 11 shows an integrated floating pool water maintenance apparatusaccording to an aspect of the invention.

FIG. 12 shows an integrated floating pool water maintenance apparatusaccording to an aspect of the invention.

FIG. 13 shows an integrated pool water maintenance apparatus above apools skimmer port according to an aspect of the invention.

FIGS. 14A, 14B and 14C show a powder-dispensing valve in three differentpositions according to an aspect of the invention.

FIG. 15 shows a spectrum of hydrophone-derived signal from the poolunder various conditions.

DETAILED DESCRIPTION

The invention provides modular components for pool water maintenancethat may each be used separately or that may be used together in anintegrated system. In some embodiments, the functionality of two or moremodules can be merged into one module. While the system is describedhere in the context of a pool or a spa, other man-made waterinstallations mentioned above may need sanitizer and chemicals tobalance the water and can benefit from all or parts of this system. Thesystem and its components can perform their intended functionautonomously or extend their capabilities by exchanging information witha database, the user, other pool owners and service personnel throughthe Internet.

FIG. 8 shows one embodiment of a system of this invention including thefollowing: a water quality measurement module 802 containing, e.g., adisposable analyte pad cartridge (not shown), a chlorine dispensingmodule 806 with its solid chlorine pucks 807, a water balance chemicaldispensing module 804 with, e.g., sealed packets of chemicals (nowshown) dispensed under water. The system of this embodiment alsoincludes the following modules disposed outside the water: an optionalpump control module 811, a user's smart phone 808 that can be used tomonitor and control the system and a mechanism that providescommunication between the modules, between the modules and the Internet810 and servers 809 used to store and process data from the system andwith the user via the Internet. In a typical use, the measurement module802 makes daily measurement of the pool chemistry and then commands thechlorine dispensing module 806 to expose trichlor pucks to water whenthere are no swimmers in the pool. Under control of the optional pumpcontrol module 811, the circulation pump is active for a period that isbased on the size of the pool, the amount of trichlor needed to bringthe free chlorine in the water to a desirable level, the amount oftrichlor left in the dispenser and can be exposed to water, the watertemperature and other parameters. This process minimizes the amount oftrichlor released to the water, enhancing the user experience, reducingcost, and reducing the accumulation of trichlor byproducts that requiresubstantial amount of the pool water to be replaced. The measurementmodule 802 can similarly instruct the chemical dispensing module 804 toopen a number of packets required to bring the water pH into desiredlevel. The sound and current consumption of the circulating pump canalert the user or service personnel to empty the pool baskets or washthe filter. The turbidity of the water can be used to turn on thecirculating pump for only the necessary time required to clear the waterthrough the filters and thus save electricity. The components arebattery operated and require no installation except for the pump controlmodule that is wired into the pump relay and draws its power from it.This important feature allows the user to deploy a level of poolautomation in minutes and save on chemicals, as well as on water use andpower.

FIGS. 1-4 show aspects of the measurement module intended to be floatedin a pool. As shown in FIG. 2, an inexpensive disposable cartridge 224is attached to a buoyancy device 222. The cartridge 224 is submerged inthe water 221 and supports a coiled strip 216 of sequential colorimetricpads 201 that can be used to test for, for example, FC using dyeN,N-diethyl-p-phenylenediamine and pH using dye phenol red. The strip216 may also contain a non-reactive pad that remains white in the waterand provides periodic optical calibration target (CT). The strip canconsist of any suitable pattern of pads, such as a repeated pattern ofpH, FC, FC, FC, CT's. The strip 216 is unwound from a bottom spool 203onto a top pic spool 202 in a manner that exposes the pads 201 and anyother test areas, as described below. A motor 218 controls the movementof the spool 202 and/or spool 203. As explained below, the colorimetricpads are exposed to water and any color change is sensed by an opticalreader assembly 208.

FIGS. 1A and 1B show a strip 108 of test pads 104 outside of ameasurement module cartridge 206 shown in FIG. 2 in side view andperspective. In one embodiment, each pad 104 measures roughly 5 mm by 5mm and is attached to a lower barrier film 101 with contact adhesive andfurther sealed in a water proof compartment made from circumferentialheat seals 103, 105, 106 and 107 formed between lower barrier film 101and a top barrier film 102. The pad is placed in an offset positioninside the sealed compartment so that it can be fully exposed to poolwater and the optical reader when that compartment is opened withouthaving to open the next sealed compartment. The term “barrier film” asdefined herein is a material that provides an appropriate barrier fromliquid water and water vapor to insure the chemical stability of itscontent over its intended field storage duration. The laminated barrierfilm can be constructed from specialized suitable transparent film thatresists both water and water vapor, allows heat sealing and contains apeel layer. For example, in one embodiment the transparent barrier filmconstruction consists of the following layers from the outside in: (1) A12-micron biaxially oriented polyester; (2) A vapor deposited aluminumoxide layer as a H₂O barrier; (3) An adhesive 50 micronpolyethylene/polybutylene blend as the inside heat seal and peel layer.The waterproof storage compartment is created by a heat seal along thesides 105 and 103 as well as cross seals 106 and 107. Once the top andbottom film are pulled apart under water, the content of the storagecompartment is exposed to water. The film is used to carry the exposedpads 109 until the cartridge is fully used and disposed.

FIG. 4 shows the top of the measurement module cartridge 401 and watersealed optical reader assembly 403 submerged in water 402. As the pickupspool 408 pulls the film strip over platen 409, each sealed pad 410 ismoved to position 417 where it is exposed to pool water for a briefperiod of time and then to position 418 where its color is read by theoptical reader assembly 403. To expose the pads 410, the top film 412 ispulled away from the bottom film by moving over wedge 419 and pin 411while the bottom film 415 carrying the pad is forced by tension createdby the pulling to remain on the platen. This action disrupts three heatseals 103, 105 and 107, as shown in FIG. 1, and the pad 410 that waspreviously completely protected from water by the barrier film isexposed to the pool water. The clear top film is pulled under theoptical reader window 407 and, after rolling on pin 413, reunites withthe bottom film, trapping the used pads 416 as they are being wound onpickup spool 408. Alternatively, motor driven pinch rollers can pull thefilm instead of the reel. Pad 414 in position 418 is illuminated bymultiple colors sequentially generated by multicolor LED 404. The colorsare selected to optimally interact with the color of the pads to providethe best colorimetric data. For FC and pH the colors of red, green, bluewere selected. Other LED colors may be selected to optimize thecolorimetric response for a particular test pad assay. The light fromthe LED is formed by aperture 405 to create an illumination circle onthe pad and the reflected light is analyzed by a photodiode 406 inoptical reader assembly 403. The color information is captured andprocessed by the on board computer described later. An additionalphotodiode with a field of view on the side the pad can be used to watchfor a dark alignment mark be printed on the strip to help the systemstop the motor when a colorimetric pad is centered under the photodiode406.

Referring again to FIG. 2, pulling the strip 201 through the platen 207as described above exposes one pad at a time. The pickup spool 202 inthe disposable cartridge 224 is driven from its center by a shaft drivenby a gear motor 218 disposed in buoyancy device 222 through a watertightcoupling. The motor and motor drive electronics are capable ofmonitoring current and pulse width modulating the current to controlmotor speed, such as shown in FIG. 3 as elements 313 and 314,respectively. The optical assembly is also shown as part of the systemin 310 and 311 interacting with pad 312 in FIG. 3. Onboardmicrocontroller 302 controls the operation. This system is batteryoperated, as shown by battery 215 in FIG. 2 and battery 301 in FIG. 3.The system can be floated in the pool with most of it submerged in thepool water where the buoyant top of the watertight enclosure 222provides the module its orientation in the water. Without themoisture-proof individual packet, the measurement pad would be quicklydegraded by water and humidity and would no longer be suitable foraccurate analyte reading. The continuous strip of packets, thenon-stretchable water and vapor barrier film that can still be peeledapart when pulled through pins, the method of exposing them one at atime while still submerged in the water or exposed to humidity, theability to operate this system for an entire pool season on four AAbatteries and sell it for less than $100 (compared to commercial watertesting systems in commercial pools costing thousands of dollars) andrequiring no electrical or plumbing modifications to the pool makes thissystem an affordable and practical autonomous pool water qualitymonitoring system that can easily be user deployed.

Continuous daily chlorine monitoring as part of an integrated chlorinedosing system affords the system the ability to calculate chlorinedemand. If the demand increases unexpectedly, it often signals animpending algae bloom that can be addressed by adding algaecides beforethe problem requires more drastic intervention such as complete poolwater replacement.

The FC concentration and pH of the pool near the surface of the waterare affected by sunlight and outgassing. In order to measure the bulkwater rather than this surface water, the module also incorporates atube with a one-way valve that utilizes the natural bobbing motion ofthe module in the pool to circulate deep pool water into the measurementmodule cartridge 224. Alternatively, a fin next to the measurementchamber can circulate nearby water based on gentle bobbing of the modulein water.

In FIG. 3, the battery operated measurement module is controlled bymicroprocessor 302 with associated memory and control circuits. Thiscontrol and communication system with its attendant sensors can beincorporated into any of the modules described below so that eachmodule's sensors and control functions can be communicated throughoutthe system. In this example, most of the sensors are built into themeasurement module that serves as a communication hub to command othermodules' operations or advise the user of certain actions that should beperformed.

The measurement module may further incorporate a 3-axis accelerometer303 to measure water movement indicative of swimmers. Accelerometer 303generates and communicates an orientation to microprocessor 302. It mayfurther incorporate a hydrophone 304 (described below) that capturessplashing sounds of swimmers. The presence of swimmers can be used tostop chemical dispensing into the pool, or alert the pool owner ofpotentially unsafe use of the pool by underage swimmers.

The measurement module may further incorporate a light sensor 305 tomeasure sunlight exposure. Light sensor 305 generates a sensed lightsignal and sends it to microprocessor 302. Sunlight degrades chlorine inthe pool and this information can be used to determine when to dose andhow much chlorine is needed based on current or historical sunlightexposure.

The measurement module may further incorporate a temperature probe 310for generating a water temperature signal and sending the signal tomicroprocessor 302. The water temperature information may be used, e.g.,to determine the rate of chemical reactions and outgas sing that consumechlorine in the water, which is temperature dependent. The length orextent of exposure of solid chlorine to the water is adjustedautomatically or by the user based on this information.

In addition to the water temperature probe 310, the measurement modulemay further incorporate an air temperature probe 311 that generates andsends an air temperature signal to microprocessor 302. The informationfrom these sensors, when combined with wind and relative humidity dataobtained from an Internet weather service, allows the device tocalculate the evaporation rate in order to estimate the refill rate thatincreases the total alkalinity and calcium hardness from fill water sothat remedial action may be taken.

The hydrophone (or water coupled microphone) 304 can pick up sounds inthe water, and the microprocessor 302 can extract features from thesesignals. FIG. 15 illustrates the frequency spectrum derived by FFTprocess for the hydrophone-derived signal 1504 where distinct swimmeractivity can be seen in the 800-1000 Hz region when compared to spectrum1501 showing similar spectrum with no swimmers in the pool. Spectrums1502 and 1503 illustrate the frequency spectrum derived by FFT processfor the hydrophone-derived signal where the circulation pump is activeat slower and faster speed, respectively, can be seen in the 100-300 Hzregion when compared to showing similar spectrum 1501 with the pump isnot active. The system can learn the exact sound of each pool bymonitoring the sound and comparing it for any acoustic condition. Inaddition to the frequency fingerprint, the system can apply machinelearning algorithms such as Hidden Markov Models to determine whethersomeone jumped into the pool or is swimming in the pool so that thesystem can avoid dosing the water with chemicals or releasing gas. Soundsignals from the hydrophone 304 can also be used by the microprocessor302 to determine whether the filter pump is on so that the system candispense chemicals or make measurements after a suitable delay to insurewell circulated water to disperse the chemicals. Sound signals from thehydrophone 304 can also be used by the microprocessor 302 to infer thefilter pump speed and load from which the state of the filtration systemcan be deduced so that the system can alert the user or service personto clean the filters, empty the baskets, and/or address unusual bearingsounds from the pump that signal imminent pump malfunction. Themicrophone 304 can also identify rainfall that indicates water dilutionrequiring chemical dosing adjustment, the sound of a cover being pulledover the pool that reduces chemical need but may trap floating modulesunder the cover, and any other activity that generates acoustic energyin the pool.

The measurement module may further incorporate an acoustic based orultrasound based transducer 309 in addition to the hydrophone 304 thatcommunicates with other similarly equipped nearby modules to controlthem or receive their status. These communication links are illustratedin FIG. 8 as elements 812 and 813.

The measurement module may further incorporate RF transmitters such asBluetooth 306 (aka BLE), cellular modem, 307 or Wi-Fi 308 with theirrespective antennas. These RF communication devices are used tocommunicate between similarly equipped modules (see elements 814, 815and 817 in FIG. 8), to the Internet via Wi-Fi or cellular modem (Seeelement 818 in FIG. 8) or BLE via a BLE-to-Wi-Fi bridge or to the user'ssmartphone via BLE or Wi-Fi (see element 816 in FIG. 8).

The system can be coupled via RF link to the Internet from which it canreceive further environmental information from a weather servicedatabase (pollen count, sun coverage including UV index, rain fall,conditions leading to algae bloom, temperature, wind, relative humidity,etc.). Such local weather conditions can be used to provide data toestimate chlorine demand and the impact to water clarity from blown-indebris.

Information from multiple systems in pools in the same locale can beanalyzed together to further increase the reliability of any one systemsince pools in the same area are exposed to the same environmentalconditions. This collaborative network of system sensors provides eachsensor the context necessary to interpret its measurement data andmeasurement frequency strategy to further optimize the water treatmentas described below.

These sensors and others described below, the microcontroller,batteries, motor, motor drive and communication modules can also beincorporated in a similar manner to other modules in the systemdescribed below.

Puck Based Chlorine Dispensing Module

FIGS. 7A and 7B show two configurations of a floating chlorinedispensing module (718 and 719, respectively) that may be used alone oras part of a system of other modules, as described above. The chlorinedispensing module has a buoyant top 709 that enables the module to floatin the pool water 717. The chlorine dispensing module has a battery 701and contains suitable disinfectant such as trichlor, or bromine pucks,granules or powder 702. For example, the trichlor pucks based systemcontrols the appropriate amount of FC dissolving in the pool water,either from a user command or in response to information from a waterquality measurement module as described above. The automatic dispensingfloating module contains a motor 704 operated mechanical shutter made upof a two nested slotted 715 and 714 cylinders that can rotate withrespect to each other. As shown in the configuration of FIG. 7A, themotor 704 of module 718 has rotated the outside cylinder so the contentof the inner cylinder is exposed to pool water through slots 702. Asshown in the configuration in FIG. 7B, the motor 704 of module 719 hasrotated the outside cylinder so that the outside cylinder's slots nowocclude the inner cylinder slots and the module's contents are shieldedfrom the pool water. In this manner, the module's electronics controlmodule 710 can control the amount of FC delivered to the pool water fromthe trichlor pucks in the module.

Current floating dispensers are the most popular form of dosing pools.They have slits that are manually set by the user to adjust theiropening and hence control the amount of sanitizer dissolved from theunit into the pool water. However, many factors affect the chlorinedemand in a pool: amount of sunlight which breaks down chlorine, swimmerload, pollen and leaves blown into the pool, rain water, algae growth ifinsufficient chlorine levels are maintained, and skin cells, suntanlotion, and other debris caught in the filter. To complicate matters,the rate of chlorine dissolving from these dispensers or from an inlinechlorinator is also affected by the surface area of the slits exposingpucks to water, the number of pucks in the floating dispenser, theirsurface area that changes as they dissolve, water temperature,circulating pump activity which tends to increase the dissolving rate tomention but a few. Clearly users are not able to manually adjust thesetting on the floating dispenser to accommodate all these factors whichresults in either under dosing with its associated health risk andpossible algae bloom or over exposure which results in burning eyes,bleached hair and swim wear, extra cost of chemicals and faster build-upof CYA, a residual part of the trichlor molecule, which reduces theeffectiveness of chlorination and eventually requires water dilution toreduce its concentration, often in excess of thousands of gallons in atypical in ground pool.

The present invention incorporates all of these measured variables aswell as a daily measurement of chlorine level to dissolve the preciseamount of chlorine in the pool on an hourly basis. It measures directlyor receives via intra-module communication described above variablessuch as water temperature, current FC levels, time of day, exposure tosunlight, pool usage, presence and activity of other oxidizing equipmentsuch as salt water chlorine generators or ozonators, circulating pumpactivity, historic FC consumption, pool size, weather, rainfall, andcomputes the amount of time to open the shutter on the FC dispensingunit when people are not using the pool to reduce their encounter withundiluted chemicals and thus creates an ideal swimming experience.

Unlike existing floating dispensers that must be loaded with pucks oftrichlor requiring the user to touch the highly oxidizing and odorouspuck, this unit utilizes a cartridge that consists of solid or granulartrichlor wrapped in a water dissolvable film in order to allow the usersafe and pleasant handling of this chemical and avoiding the over 400consumer injuries each year from such pool chemicals as reported by theEPA. The water dissolvable film 716 (shown in FIG. 7C) wraps thesanitizer pucks 702 and fits into the dispensing unit 708. The waterdissolving film can be made of polyvinyl alcohol (aka PVOH or PVA).

Concentrated trichlor in this type of popular floating dispenser oftengenerates by-products including nitrogen trichloride that has a pungentodor that most people associate with the unpleasant smell of chemicalsin and around pools. The present invention traps this gas generated bytrichlor in the reservoir in a sealed compartment 709 at the top of thedispenser and utilizes a solenoid or motor activated valve 711 to ventit through opening 712 when the pool is not in use such as nighttime inorder to minimize this very unpleasant odor while the pool is in use.The floating dispensing module gathers pool use information from one ormore of the sensors described above to ascertain if swimmers are in ornear the pool. These sensors were described above in the water qualitymodule that can communicate this information to this module or the samesensors can be built into this unit.

A magnet 707 is placed on top of the cartridge and a magnetometer in theon board electronics 710 measures the magnetic field that changes as thetrichlor is dissolved and the magnet moves further from its homeposition. This allows the chlorine dispenser to alert the user toinstall a new cartridge before the unit runs out of chlorine.Alternatively, the hydrophone and ultrasonic transducer described abovecan be used to reflect sound from the top of the trichlor stack andcalculate the height of the stack by measuring the time for the echo toarrive at the hydrophone.

Trichlor pucks in contact with pool water will dissolve at varying ratesdepending on the water flow and other parameters noted above and thusthe flux of chlorine cannot be completely stopped. In another embodimentshown in FIG. 11, a complete system 1100, floats with water line 1110,where the motors and electronics are housed in the unit's cap 1111.System 1100 dispenses trichlor from a stack of slow dissolving pucks1101 which can be completely removed from contact with pool water bylifting them into a bell jar like reservoir 1104. The pucks 1101 have ahole in the middle through which worm screw 1102 (shown in phantom)passes. The worm screw engages a lift plate 1103 to lift the stack ofchlorine pucks into the reservoir 1104 and lower them to the dispensingarea 1105 where they are exposed to the water through slits 1106. Theworm screw is driven by a motor connected to a microprocessor capable ofmeasuring the current in the motor and hence the limits of travel of thelift plate which stalls when fully lowered or raised. The number ofturns between the position of fully lowered lift plate to its fullyraised position provides a measure for how much of the pucks on thestack have yet to be dissolved in the pool water and when the user mustbe alerted to refill the device.

The gas in the reservoir is produced by the dissolving trichlor pucks orcan be pumped in. When the pucks are raised above the water into thereservoir's gas layer, the chlorine dispensing into the water ceasescompletely. The gas layer height can be controlled by the on boardmicroprocessor and kept right below the lift plate in its up mostposition by using a water level capacitive sensor as described in US2013/0313204 (now U.S. Pat. No. 9,034,193). In order to control thedevice's buoyancy and maintain the gas at the right level as measured bythe capacitive sensor described above, a pump (not shown) or a motoractuated valve 1112 can be opened to vent the gas when no one is nearthe device. It can be appreciated that any of these modules can beintegrated into one unit or deployed independently.

This embodiment also includes chemicals in packages on a folded strip1120. To dispense these chemicals, the strip is pulled by pinch rollers1107 past ceramic blade 1108 to disrupt the packages and dispense thechemicals they contain.

Submerged Powdered or Gel Chemical Dispensing Module

Other chemicals may need to be dispensed into the water installation.FIG. 8 shows a floating water balance chemical dispenser module 804 witha buoyant top utilizing cartridges, e.g., a disposable cartridge shownin FIG. 5. FIG. 5 shows the cartridge 501 containing a strip 502 ofpackets of chemicals enclosed in a barrier film. This film does notreact with its contents and minimizes moisture entering the packet andreacting with the chemicals stored within it (and thus degrading theirperformance or activating them, causing gas release or package failure).Each chemical has its water exposure limit over its intended in-fieldand shelf-life use case. The chemicals can be in solid, granular,powder, gel or liquid form. For example, most chlorine-based sanitizersoutgas and begin to decompose when exposed to any moisture. Theoutgassing of the chemicals compromises the packet seal, which in turnlets more water in and activates the chlorine that can completelydestroy the film. Therefore, in one embodiment this film is speciallyconstructed as a multilayer laminate and filled and sealed with specialequipment that does not compromise the film's barrier properties. Forexample, the laminated chemical barrier film can be constructed from thefollowing layers from the outside in: (1) An outer layer protecting thealuminum foil such as 12 micron biaxially oriented polyester; (2) Anadhesive; (3) A moisture barrier such as 0.009 micron aluminum foil; (4)An adhesive; (5) A 50 micron polyethylene/polybutylene blend to providethe peelable heat seal and protect the aluminum from the inside of thepacket.

The top and bottom film are peeled apart by winding them on two gearedbobbins 503 and 504 under the control of the embedded controller's gearmotor (in the buoyant compartment above the cartridge 501, not shown inFIG. 5) coupled to the gear via rotating shaft 507 and worm gear 508.When the shaft rotates the worm gear, the bobbins rotate in oppositedirections pulling the top film and the bottom film apart and separatingtheir heat seal. Separation of the film pieces exposes the chemicals inthe packet and allows them to dissolve in the water, as shownschematically by arrow 506. Alternatively, slitting blades can disruptthe moisture impermeable packets and disperse their content into thewater. The cross seal between packets (similar to that shown as element107 in FIG. 1) requires more force than the side seals. The increasedforce can be used by the on board processor which monitors the motorcurrent to signal that a full packet has been peeled.

In yet another embodiment, the packets are driven by two textured pinchrollers (such as the pinch rollers 1107 shown in FIG. 11) along thesealed edges of the strip of packets while blades (such as, e.g., theceramic blades 1108 shown in FIG. 11) slice the top of the packet as itmoves along so that its content can be dispensed into the pool water inresponse to an integrated measurement unit (such as unit 1109 in FIG.11) as described above. Alternatively, a wheel with sharp spokes isspring loaded into the packets and pokes holes in the film to allowwater to mix with the enclosed chemicals and disperse them in the pool.

The chemicals in the packets might consist of trichlor, dichlor, calciumhypochlorite, lithium hypochlorite, sodium hydroxide (lye) to drive thepH up to balance the trichlor pH down effect, algaecides or phosphateremovers to prevent algae growth, sodium bicarbonate (baking soda) toraise the total alkalinity (TA), or sodium bisulfate or hydrochloric orsulfuric acids to lower the pH when using hypochlorite chlorine, orpotassium monopersulfate (MPS) non-chlorine shock. Each of thesechemicals is packaged in its own cartridge that is sensed by thechemical dispensing module via on board optical detectors detecting anoptical pattern at the top of the cartridge.

In yet another embodiment of the floating integrated dispensing unit1200 as shown in FIG. 12, the powder chemicals are stored in acollapsible bladder 1201 made of suitable water impermeable film.Dispensing chemicals whose density is close to water from a submergedrigid dispenser of a floating unit changes the buoyancy of the unit andcan cause it to tip over. In this embodiment, the chemicals are storedin bladder 1201. The bladder changes its volume as material is dispensedand pool water enters the device through holes 1215 and thus keeps thedevice's buoyancy nearly constant and floating at the same level overthe water 1210. The powder is dispensed into the water using a dispenser1212 driven by motor 1209 in a waterproof compartment with electronicsand battery power source. The dispenser prevents water from entering thebladder and is described further in FIG. 14 below. The user can fill thebladder through filler cap 1208. A suitable magnet 1204 attached to thebladder wall and magnetic field detector 1205 are used by the on boardmicroprocessor to calculate the remaining material in the bladder. Thechemical dispenser can thus automatically dose the pool when it receivesa command from the water quality measurement module using thecommunication mechanism described above.

The chemical dispenser can monitor the cartridge becoming empty bysensing the motor current drop due to lower torque with no film to peeland reporting back to the user to replace the cartridge.

For example, calcium hypochlorite packets and sodium bisulfate packetsin two different cartridges can be controlled independently depending onwhat is needed, or in a fixed ratio in the same cartridge.

As an additional example, lithium hypochlorite and baking sodacartridges can be used in different cartridges.

As an additional example, dichlor and baking soda can be delivered fromtwo different cartridges.

As an additional example, potassium monopersulfate (MPS) non-chlorineshock and lye can be delivered from two different cartridges. Thiscombination could be used in the non-halogen Nature² system that usessilver and zinc ions in conjunction with MPS as an EPA-approveddisinfectant.

As an additional example, fragrance or other chemicals can be deliveredfrom a cartridge.

Multiple cartridges of one chemical such as trichlor can be deployed sothat when one is empty the full one is deployed and the user has aperiod of time before having to replace the empty cartridge.

Submerged Liquid Chemical Dispensing Module

FIG. 12 also shows a liquid dispenser for reagents such as muriatic acid1216 to adjust for calcium hypochlorite powder. The liquid reagent isstored in a bladder 1202 adjacent to bladder 1201. It is filled throughcap 1217. It has a similar magnet 1220 and sensor 1221 to detectremaining reagent in the bag. It is dispensed through bellows pump 1218driven by motor 1219 in a housed in watertight compartment with itselectronics and power source.

Non-Submerged Chemical Dispensing Module

In some situations it is desired to dispense the chemicals from anon-floating module. It should be noted that the mechanisms describedabove can be used in this configuration where the unit 1301 as describedin FIG. 13 sits on top of a skimmer port held with flange 1312 or on thepool's edge with its dispensing ports right over the water 1315 orfloating on a buoyant platform above the water. The measurement unit1303 is as was described above and is incorporated into this unit whereat least the measurement area (i.e., where the pads are opened) issubmerged in water. Water-sealed compartment 1318 contains theelectronics to monitor the pad, the microphone, temperature sensor,water flow sensor, water level sensor, and the pad drive motor. Cassette1319 contains the sealed and used pad and film as described above. Cable1320 connects the electronics in 1318 to the main electronics controlbox, and two of its leads serve as capacitance water height detector1311 as described in US 2013/0313204 (now U.S. Pat. No. 9,034,193). Thewater level measurement allows the unit to automatically stop dispensingchemicals if it is out of the water or while deployed on the skimmer toreport back to the user if pool water level is too high or too low. Thetemperature is used to determine the chemical dissolution rate andreport to the user. The water flow detector is used to insure thatchemicals are added only with the pool's circulating pump is active andthus insure that the chemicals dispensed are rapidly dispersed in thepool water. The microphone is used as both pump and swimmer detector toinsure that chemicals are only added when no one is in the pool as ameasure of safety. The measurement unit pads are protected from waterand humidity with the water impermeable film, and are exposed to poolwater one at a time as described above.

The calcium hypochlorite reservoir 1304 is filled via port 1314, and ithas a dispensing port 1313 with dispensing mechanism 1321 describedfurther below. The reservoir has an angled bottom to insure that all thepowder flows to the dispenser via gravity.

The powder dispenser 1321 is shown in 3 positions in FIGS. 14A-C. In theload position shown in FIG. 14A, the sealed chamber is loaded with afixed known volume of powder from a reservoir via port 1402. It issealed from water via wiper blades 1403 and 1404. It is rotated in adrum 1405 via an electric motor. In the dispense position shown in FIG.14B, the drum 1404 is rotated 180 degrees, and the powder is droppedinto the water via port 1406. If this dispenser is operated under water,it is imperative that water will not mix with the dry powder. Therefore,in the water empty position shown in FIG. 14C, air from a small on boardpump is routed through port forcing the water that may have entered thedispensing chamber while it was open to dispensing port 1406, throughwater evacuation hole 1408. The dispenser having been emptied from watercan be now be rotated to the load position of FIG. 14A to complete thedispense cycle.

Adjacent muriatic acid reservoir 1305 with its filler port 1306 utilizesa bellows pump 1307 at is base to dispense a measured amount of acidinto the water via port 1316.

In addition the module can incorporate a camera and light 1317 to take apicture or sense reflectivity and color of the skimmer basket and alertthe user or service personnel when it is full of debris and requiresservice.

The module may incorporate other sensors, communication and processingmeans as described above.

In addition to the example described above, this unit or the submergedunits can be used in saltwater pools where chlorine is generated byelectrolysis. The unit can measure and balance chlorine by adding itsown chlorine when peak demands require it, turn off the generator via RFsignal to a remote relay unit when too much chlorine is generated andadd acid to balance the pH of the pool water.

Turbidity

As shown in FIG. 9, the floating module 901 may further incorporate anoptical turbidity measurement of pool water using a photodiode 907 witha pinhole, aimed through lens 906 through the water at target 902. Thisultra-low power turbidity measurement utilizes sunlight 913 toilluminate the target through the pool water. Small particles primarilyin the 10-1000 micron range in the pool water scatter sunlight 912reflected from the target toward the collecting lens 906. That scatteredlight reduces the contrast between the black and white portions of thetarget in an amount proportional to the concentration of particles inthe water. An eccentric cam moves the spring mounted photodiode 907laterally a small distance causing it shift its focus between the white903 and black 904 portions of target 902. The white portion serves as areference measuring the intensity of the sunlight and the black portionallows the photodiode to see the scattered light. The ratio betweenthese two measurements is proportional to the scattered light in thepool water and is further used to control the filtration cycle of thepool. By turning on the pump only when there are particles to befiltered and stopping the filtration when they have been removed fromthe water, considerable power can be saved.

Pump Control Module

FIG. 6 shows a pump control module that may be used alone or inconjunction with the other modules described above. In one embodiment,an electronic module 601 switches on the filter pump when receiving anRF signal from the water quality measurement module to, e.g., keep thewater turbidity below a target level. The unit's relay 607 can be wiredin parallel with the pump control relay 604 and 605 without runningadditional wiring to the pump. The activation of the pump controllerbased on turbidity instead of hard wired timed operation of the pumpallows for optimal use and significant savings of electrical power.

The pump controller senses the voltage via terminals 603 and 604 andcurrent via monitor coil 606 around the pump activation wire by the pumpand compares it to previous records. Increase in current over a few dayssuggests that the skimmer and pump baskets might be clogged with leaves.Increase in current over a longer period of time indicates when thefilters develop backpressure and require cleaning. This information iscommunicated to the user or to a service provider via the RFcommunication link such as shown as element 817, 818 and 809 in FIG. 8,which makes it available on a web page hosted on the servers, or viaelements 817 and 816 directly to a nearby smart phone.

FIG. 10 shows a typical spa configuration of the system where severalmodules and an alternative sensor can be combined for a particularsystem configuration. In this configuration a single enclosure 1001 issuspended via strip hanger 1004 off the ledge of a typical spa 1003. Thebracket is very thin strip so that if a cover is used, it will notcreate an opening for heat and steam to escape. The device is suspendingin fixed position with respect to the spa and its water 1002 that riseswhen bathers enter the spa and are detected via capacitance electrodes1007 as described in US 2013/0313204 (now U.S. Pat. No. 9,034,193). Themodule further incorporates an FC dispenser as described above usingsmaller cartridges (typically around 1″ diameter) and a water pHbalancing sodium hydroxide packaged in the film barrier packets 1010 incartridge 1009 driven by rotating shaft 1011 driven by motor 1012 in thewater tight enclosure 1013 and further controlled by the onboardelectronics 1014 powered by battery pack 1015. In this configuration thegas generated by the warm water interaction with the trichlor when theFC dispenser is closed is vented to the outside via tube 1006 connectingthe top of the FC dispenser to thin venting channel 1005 built into thestrip hanger 1004 and thus avoids the accumulation of noxious gas underthe spa cover which can further deteriorate the spa components.

In an alternative embodiment, the system utilizes a cartridge of dichlorwith or without a pH modification cartridge since dichlor is more pHneutral. The dichlor is packaged in individual packets the waterimpermeable film strip as described above that are peeled or sliced orpoked to allow the content to dispense to the spa water.

This system, or portions thereof, can be used in a spa in conjunctionwith other devices used to reduce water contamination such as ozonators,salt water chlorine generators, UV lamp sanitizers and turn them on onlywhen they are needed. This extends their field life and reduces energyconsumption. Ozone consumes chlorine so is best used when there isbather load to oxidize and not used when chlorine is providing abackground disinfectant level in between soaks.

What is claimed is:
 1. A water quality management system for a pool, thesystem comprising: a flange adapted to engage a skimmer port of thepool; a water quality measurement module extending from the flangeadapted to monitor water quality of the water and to send water qualityinformation to a controller; and a communication mechanism configured toprovide communication among the controller, the water qualitymeasurement module, and a user.
 2. The water quality measurement systemof claim 1 wherein the water quality measurement module comprises ameasurement area adapted to be submerged in water within the skimmingport.
 3. The water quality management system of claim 2 wherein thewater quality measurement module comprises a plurality of colorimetrictest pads disposed in the measurement area, each test pad enclosed in awater and vapor-proof barrier.
 4. The water quality management system ofclaim 3 further comprising a cassette in the measurement area, theplurality of colorimetric test pads being disposed in the cassette. 5.The water quality management system of claim 3 wherein the water qualitymeasurement module further comprises a sensor disposed in themeasurement area and adapted to sense a color change in a test pad forprocessing by the controller.
 6. The water quality management system ofclaim 3 wherein the water quality measurement module further comprises amotor adapted to expose a test pad to water to permit water to reach thetest pad.
 7. The water quality management system of claim 2 wherein themeasurement area comprises a water-sealed compartment and water qualitymonitoring electronics disposed within the compartment.
 8. The waterquality management system of claim 7 wherein the water qualitymonitoring electronics comprise a water quality sensor.
 9. The waterquality management system of claim 7 further comprising a cassetteengaged with the water-sealed compartment and a plurality ofcolorimetric test pads disposed in the cassette, each test pad enclosedin a water and vapor-proof barrier.
 10. The water quality managementsystem of claim 9 further comprising a motor disposed in thewater-sealed compartment and adapted to expose a test pad to water topermit water to reach the test pad.
 11. A cassette for use with a waterquality management system for a pool, the cassette containing aplurality of colorimetric test pads, each test pad enclosed in a waterand vapor-proof barrier, the cassette being adapted to operativelyengage with a compartment of the water quality management system, thecompartment containing a sensor adapted to sense a color change in atest pad.
 12. The cassette of claim 11 wherein the cassette is furtheradapted to operatively engage with a motor in the compartment, the motorbeing adapted to export a test pad to water in the pool.
 13. A method ofmonitoring water in a pool, the method comprising: engaging a flangewith a skimmer port of the pool, the flange supporting a water qualitymanagement system; sensing a quality of the water with a sensor in thewater quality management system; and communicating the quality of thewater to a user.
 14. The method of claim 13 wherein the sensor isdisposed in a measurement area of the water quality management system,the method further comprising submerging the measurement area in thewater.
 15. The method of claim 14 wherein the water quality managementsystem comprises a plurality of colorimetric test pads in themeasurement area, each test pad enclosed in a water and vapor-proofbarrier.
 16. The method of claim 15 wherein the sensing step comprisessensing a change in color of a test pad.
 17. The method of claim 15further comprising exposing a test pad to the water.
 18. The method ofclaim 17 further wherein the exposing step comprises operating a motorto expose a test pad to the water.
 19. The method of claim 15 whereinthe test pads are disposed in a cassette.
 20. The method of claim 19wherein the water quality management system further comprises a sealedcompartment engaged with the cassette in the measurement area, thesensor being disposed in the sealed compartment, the sensing stepcomprising sensing a change in color in a test pad with the sensor. 21.The method of claim 20 wherein the water quality management systemfurther comprises a motor disposed in the sealed compartment, the methodfurther comprising operating the motor to expose a test pad to thewater.